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NFSv4.1/pnfs: Fix atomicity of commit list updates

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pnfs_layout_mark_request_commit() needs to ensure that it adds the
request to the commit list atomically with all the other updates
in order to prevent corruption to buckets[ds_commit_idx].wlseg
due to races with pnfs_generic_clear_request_commit().

Fixes: 338d00cfef ("pnfs: Refactor the *_layout_mark_request_commit...")
Cc: stable@vger.kernel.org # v4.0+
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
This commit is contained in:
Trond Myklebust
2015-07-31 16:24:30 -04:00
parent 74d33293e4
commit 86d80f9734
3 changed files with 37 additions and 12 deletions
Download Patch File Download Diff File Expand all files Collapse all files

15
fs/nfs/internal.h
View File

@@ -490,6 +490,9 @@ void nfs_retry_commit(struct list_head *page_list,
void nfs_commitdata_release(struct nfs_commit_data *data); void nfs_commitdata_release(struct nfs_commit_data *data);
void nfs_request_add_commit_list(struct nfs_page *req, struct list_head *dst, void nfs_request_add_commit_list(struct nfs_page *req, struct list_head *dst,
struct nfs_commit_info *cinfo); struct nfs_commit_info *cinfo);
void nfs_request_add_commit_list_locked(struct nfs_page *req,
struct list_head *dst,
struct nfs_commit_info *cinfo);
void nfs_request_remove_commit_list(struct nfs_page *req, void nfs_request_remove_commit_list(struct nfs_page *req,
struct nfs_commit_info *cinfo); struct nfs_commit_info *cinfo);
void nfs_init_cinfo(struct nfs_commit_info *cinfo, void nfs_init_cinfo(struct nfs_commit_info *cinfo,
@@ -623,13 +626,15 @@ void nfs_super_set_maxbytes(struct super_block *sb, __u64 maxfilesize)
* Record the page as unstable and mark its inode as dirty. * Record the page as unstable and mark its inode as dirty.
*/ */
static inline static inline
void nfs_mark_page_unstable(struct page *page) void nfs_mark_page_unstable(struct page *page, struct nfs_commit_info *cinfo)
{ {
struct inode *inode = page_file_mapping(page)->host; if (!cinfo->dreq) {
struct inode *inode = page_file_mapping(page)->host;
inc_zone_page_state(page, NR_UNSTABLE_NFS); inc_zone_page_state(page, NR_UNSTABLE_NFS);
inc_wb_stat(&inode_to_bdi(inode)->wb, WB_RECLAIMABLE); inc_wb_stat(&inode_to_bdi(inode)->wb, WB_RECLAIMABLE);
__mark_inode_dirty(inode, I_DIRTY_DATASYNC); __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
}
} }
/* /*

5
fs/nfs/pnfs_nfs.c
View File

@@ -863,9 +863,10 @@ pnfs_layout_mark_request_commit(struct nfs_page *req,
} }
set_bit(PG_COMMIT_TO_DS, &req->wb_flags); set_bit(PG_COMMIT_TO_DS, &req->wb_flags);
cinfo->ds->nwritten++; cinfo->ds->nwritten++;
spin_unlock(cinfo->lock);
nfs_request_add_commit_list(req, list, cinfo); nfs_request_add_commit_list_locked(req, list, cinfo);
spin_unlock(cinfo->lock);
nfs_mark_page_unstable(req->wb_page, cinfo);
} }
EXPORT_SYMBOL_GPL(pnfs_layout_mark_request_commit); EXPORT_SYMBOL_GPL(pnfs_layout_mark_request_commit);

29
fs/nfs/write.c
View File

@@ -767,6 +767,28 @@ nfs_page_search_commits_for_head_request_locked(struct nfs_inode *nfsi,
return NULL; return NULL;
} }
/**
* nfs_request_add_commit_list_locked - add request to a commit list
* @req: pointer to a struct nfs_page
* @dst: commit list head
* @cinfo: holds list lock and accounting info
*
* This sets the PG_CLEAN bit, updates the cinfo count of
* number of outstanding requests requiring a commit as well as
* the MM page stats.
*
* The caller must hold the cinfo->lock, and the nfs_page lock.
*/
void
nfs_request_add_commit_list_locked(struct nfs_page *req, struct list_head *dst,
struct nfs_commit_info *cinfo)
{
set_bit(PG_CLEAN, &req->wb_flags);
nfs_list_add_request(req, dst);
cinfo->mds->ncommit++;
}
EXPORT_SYMBOL_GPL(nfs_request_add_commit_list_locked);
/** /**
* nfs_request_add_commit_list - add request to a commit list * nfs_request_add_commit_list - add request to a commit list
* @req: pointer to a struct nfs_page * @req: pointer to a struct nfs_page
@@ -784,13 +806,10 @@ void
nfs_request_add_commit_list(struct nfs_page *req, struct list_head *dst, nfs_request_add_commit_list(struct nfs_page *req, struct list_head *dst,
struct nfs_commit_info *cinfo) struct nfs_commit_info *cinfo)
{ {
set_bit(PG_CLEAN, &(req)->wb_flags);
spin_lock(cinfo->lock); spin_lock(cinfo->lock);
nfs_list_add_request(req, dst); nfs_request_add_commit_list_locked(req, dst, cinfo);
cinfo->mds->ncommit++;
spin_unlock(cinfo->lock); spin_unlock(cinfo->lock);
if (!cinfo->dreq) nfs_mark_page_unstable(req->wb_page, cinfo);
nfs_mark_page_unstable(req->wb_page);
} }
EXPORT_SYMBOL_GPL(nfs_request_add_commit_list); EXPORT_SYMBOL_GPL(nfs_request_add_commit_list);